1. Filed of the Invention
The invention relates to a plug connection for fluid lines, comprising two intermateable coupling parts, which in the inserted state can be releasably locked.
2. Related Technology
The invention relates to a retaining part for a plug connection.
A plug connection is known, from WO 2006/018384 A1, in which a known locking principle is assumed, according to which a C-shaped retaining section of a retaining part positively encompasses retaining bars of coupling parts and is fixed in this way. In order to reduce the danger of detachment of the retaining part and simplify the assembly, in particular also in applications in which the assembly location only has a small surrounding space available, or in which at least one valve is to be integrated into the coupling parts, it is provided that, firstly, the retaining part is configured in such a way and is undetachably preassembled or preassemblable in such a way that it is axially fixed with little play and radially undetachably fixed, and, secondly, is radially elastically movable in the area of the retaining section. The retaining part in the area of the retaining section, as well as the retaining bar of the other coupling part, must be configured in adaptation to each other in order to form a positive snap-on connection acting in insertion direction, in such a way that the retaining section is moved radially outwardly by the retaining bar moving relative thereto when the coupling parts of the retaining section are plugged into each other and subsequently encompasses the retaining rods of the two coupling parts for locking purposes by means of the radial return movement toward the inside in inserted state. The retaining part is preferably configured as a one-piece annular part having an axially and radially continuous slot interruption at a point of the periphery. This known plug connection makes possible an easy, fast and convenient as well as also secure single-hand assembly. In order to reduce the danger of detachment when the retaining part is detached from the coupling parts, WO 2006/018384 provides to undetachably connect the retaining part to a coupling part via an additional, in particular ribbon-like or string-like retaining element attachable at one end to the coupling part and at the other end to the retaining part.
A plug connection of the kind described above is also known from WO 2009/156399 A1. In this document, the additional retaining element is considered disadvantageous. In order to facilitate a positioning of the retaining part and the reassembly with a low danger of detachment of the retaining part with reduced complexity, while eliminating such an additional retaining element, the retaining part is provided with a ring-shaped configuration, wherein the retaining part is fixed on at least one of the two coupling parts with a circumferentially closed annular contour in a preassembled state and encompasses at least one of the two coupling parts in assembled state. The retaining part can at the same time be preferably undetachably preassembled on a plug part, wherein it can be fixed in two positions, the preassembly position and the assembly position. It arrives from the preassembly position into the assembly position by means of a radial displacement or for disassembly from the assembly position back into the original position by means of a mutually opposite displacement. In this respect a configuration is preferred with which an annular opening enclosed by the annular contour is formed by a first circular partial opening with a central point in the area of the retaining section, and a second circular partial opening, whose central point is located within a retaining section of the retaining part, wherein the two partial openings intersect. The retaining part has necessarily an enlarged radial extension, which is considered particularly disadvantageous when only very little assembly space is available.